... (4,a -1 ,U), (1, b -1 ,U), (4,b -1 ,L), (3,a -1 ,U), (5,a -1 ,L),(3,b -1 ,L), (0,a0,U), (1, a0,L), (5,a -1 ,U), (6,a -1 ,L), (3,b -1 ,U), (1, a0,U), (3,a0,L), (4,b -1 ,U), (5,b -1 ,L), ... (19 68), Ramchandani (19 73), Karp (19 78), Gondran and Minoux (19 85), Cohen et al. (19 85), Hillion and Proth (19 89), McCormick et al. (19 89), Chretienne (19 91) , Lei and Liu (20 01) , Roundy (19 92), ... Livshits et al. (19 74), Matsuo et al. (19 91) , Lei (19 93), Ioachim and Soumis (19 95), Chen et al. (19 98), Van de Klundert (19 96), Levner et al. (19 96, 19 97), Levner and Kats (19 98), Crama et al....